Building an outdoor deck can add valuable living space and a beautiful new focal point to your backyard. With proper planning and execution, you can create a gorgeous deck for entertaining, relaxing, and enjoying the outdoors. This comprehensive guide will walk you through all the steps involved in constructing a durable, safe, and attractive DIY deck.
Planning Your Deck
Before starting your deck building project, careful planning is essential. Consider the following factors as you develop plans:
Deck Size and Layout
- How large of a deck do you want? Make sure to account for stairs, landings, etc. in the total square footage.
- What shape deck will best fit your yard? Rectangular and square shapes are most common.
- Sketch your deck plans to scale on graph paper, indicating all measurements.
- Mark deck location on the ground with stakes and string to visualize size and shape.
Deck Height
- Standard height is 12-18 inches above ground for easy access. Adjust to fit terrain.
- Consider door sill height if attaching to home to allow smooth transitions.
Decking Material
- Pressure-treated lumber is durable, affordable, and easy to work with. Pine and cedar are naturally rot-resistant options.
- Composites like Trex are splinter-free, low-maintenance, and resist weathering. More expensive than wood.
- Redwood, Ipe, and Tigerwood provide beautiful exotic hardwood decking. Require more upkeep.
Railings and Stairs
- Include sturdy railings for safety, matching style of your home.
- Stairs should be 36-42 inches wide, with stair treads at 9-11 inches deep.
Sun and Shade Exposure
- Note sun exposure at different times of day. Position deck to maximize or limit sun as desired.
- Consider adding shade elements like a pergola, canopy, or trees.
Building Permits and Codes
- Most areas require permits for decks over 200 sq ft. Ensure your plans meet local codes.
Preparing the Site
Once your deck plans are finalized, it’s time to prep the installation site:
Clear and Level Ground Surface
- Remove sod or plants in the deck footprint area.
- Dig down ~6 inches and create a flat, compacted surface.
- Lay gravel, sand, or patio pavers to create a level base.
Mark Post Hole Locations
- Mark the precise spots for digging footings based on deck plans.
- Use markings to align ledger board to house if attaching.
Call 811 to Locate Utilities
- Calling 811 before any digging gets utilities marked for free.
- This prevents dangerous and costly accidents.
Purchase Materials and Supplies
- Order lumber, hardware, fasteners, and tools needed for the project all at once.
- Delivery services can drop materials in your driveway for convenience.
Constructing Deck Supports
Deck support posts anchored on proper footings provide the foundation for everything built above:
Dig Post Holes
- Dig holes 12″-18” in diameter, with depth ~1/3 the post height above ground.
- Hole depth depends on frost line in your region. Ask at local building supply.
- Add 6” gravel base in each hole to improve drainage.
Set and Anchor Post Anchors
- Place metal anchor with integrated rebar or wood anchor in each hole over gravel.
- Fill around anchor with premixed concrete and level top. Allow 2-3 days drying time.
- Alternate option is to embed posts directly in concrete without anchors.
Position and Level Posts
- Set 4×4 or 6×6 pressure-treated posts in anchors, checking they are plumb.
- Temporary brace posts in place until beam is attached.
- Use post levelers to fine-tune posts to perfect vertical position.
Install Beam for Joists
- Nail 2×8 or larger beam to tops of posts with galvanized framing nails.
- Crown beam up slightly to allow water runoff.
- Confirm beam is level end-to-end before securing deck joists.
Adding Deck Floor Joists
Properly installed and spaced floor joists provide critical structural support for decking boards:
Mark Joist Layout
- Measure and mark where joists will sit on beam, usually 16” on center.
- Double up joists under points where railings or stairs will attach.
Cut Joists to Length
- Cut 2×8 or 2×10 joists to correct length based on deck width.
- Joists should overhang beams by 3-4” on each end.
Attach Joists to Beam
- Use galvanized joist hangers or hurricane ties to connect joists.
- Nail joists to beam through hanger with 2 rows of galvanized nails.
Install Support Blocks
- Add 2×4 blocks between joists towards center for mid-span support.
- Place blocks ~5’ from beam, screwed into joists from below.
Decking Installation Tips
Installing deck boards across joists completes the structural portion of your new deck:
Allow Lumber to Acclimate
- Let all lumber adjust to current humidity levels to prevent warping.
- Stack boards with spacers in deck area 1-2 weeks before installing.
Set Consistent Board Gap
- Use 0.25” gap spacers to provide proper drainage between boards.
- Match gap width across entire deck for a consistent look.
Work from One Direction
- Work outward in one direction from house to avoid stepping on installed boards.
- This prevents loose, uneven decking.
Stagger Board Ends
- Staggering board end joints strengthens deck and minimizes seams aligned.
- Each new row should be offset from previous row by 1⁄3 to 1⁄2 a board length.
Secure Boards with Proper Screws
- Use 2-3” exterior-grade, corrosion-resistant decking screws.
- 2 screws at each joist creates a sturdy deck surface.
Adding Railings and Stairs
Railings and stairs put the finishing functional touches on your new outdoor living space:
Mark and Install Railing Posts
- Set 4×4 railing posts in doubled up joists using post anchors or notches.
- Ensure posts are plumb and properly anchored before installing railing.
Build Railing Frame
- Construct railing frame securing top and bottom rails to posts. Check for level and plumb.
- Include balusters spaced no more than 4” apart for safety and code compliance.
Create Stair Stringers
- Use 2x12s to form stair stringers with runs and rises sized per plan.
- Mark and cut out stringer notches for tread depth and overhang.
Install Stairs
- Anchor stringers to deck posts and landing posts with galvanized hardware.
- Install treads leaving 3⁄4” nosing overhang and risers fully enclosing stringers.
Finishing Touches
Apply final touches to maximize your deck’s beauty and functionality:
Seal Decking
- Apply water-repellent sealant to protect against weathering and prevent splintering.
- Allow sealer to fully dry before using deck. Reapply annually.
Add Exterior Lighting
- Install downlights on posts pointing at stairs for visibility.
- Low-voltage lighting around posts and rails creates ambiance for nighttime.
Furnish and Decorate
- Comfy outdoor furniture and decorative elements personalize your space.
- Potted plants, weather-resistant rugs, and art enhance the deck.
Building your own deck is an ambitious project, but extremely rewarding. Refer to this guide throughout each phase of construction. Taking it step-by-step while following codes and best practices will result in a gorgeous and long-lasting outdoor living space you can enjoy for years to come. Feel free to get in touch with any questions that come up on your deck-building journey!
Frequently Asked Questions About Building Outdoor Decks
Here are answers to some common questions about constructing your own outdoor deck:
How much does it cost to build a deck?
Deck construction costs typically range from $25 – $45 per square foot depending on size and materials selected. Pressure-treated wood is the most economical, while composites like Trex offer a higher-end look for $35-$70 per square foot.
What size beams and joists are needed for a deck?
For beams, a minimum of two 2×8 boards nailed together is recommended. 2×8 or 2×10 joists are sufficient for most residential decks, spaced 16 inches on center. Confirm sizes via an online deck joist span calculator.
Should you use treated or cedar wood for decking?
Pressure-treated pine is the best value choice. Naturally rot-resistant cedar with its attractive appearance is also excellent for decks, though more expensive. Redwood and Ipe offer high-end exotic hardwood options.
What is the best time of year to build a deck?
It’s optimal to construct a deck in mid-spring to early summer when minimal rain allows concrete footings to cure properly. You also want to avoid extreme heat that can warp lumber.
How long does it take to build a deck?
A basic 12×12 foot deck can be built by two people in 3-5 days. Allow 7-10 full days for a more substantial 300 square foot deck. Remember extra time for concrete curing, securing permits, and planning.
Can I install a deck myself without experience?
Building a quality deck requires some carpentry skills, but with proper planning and by following code standards, you can absolutely DIY one. Patience and attention to detail are key. Consider asking an experienced friend to assist.
Let me know if you need any clarification or have additional questions about how to build an amazing outdoor deck!